Electric furnace.



No. 803,147. PATENTED OCT. 31, 1905 E. APPLBBY.

ELECTRIC FURNACE.

APPLICATION FILED JAN. 28, 1905.

UNITED srArns PATENT OFFICE.

ELECTRIC FURNACE.

Specification of Letters Patent.

Patented Oct. 31, 1905.

Application filed January 28, 1905. Serial No. 243,134.

To all whom, it may concern.-

Be it known that I, EDWIN APPLEBY, a subject of the King of GreatBritain, and a resident of Chicago, in the county of Cook and State ofIllinois, have invented certain new and useful Improvements in ElectricFurnaces, of which the following is a specification.

This invention relates to electric furnaces, and has particularreference to a type which 1iosciiiseful for the manufacture of calciumcar- The main objects of my invention are to provide a form of electricfurnaces in which a limited zone of intense heat is formed by means ofan electric arc and which is provided with improved mechanism forcontinuously and uniformly supplying to th e said zone the granularconstituents from which the carbid is formed, such as mixed powderedlime and coke, together with improved means for continuously withdrawingfrom the Zone of activity the newly-formed carbid, all withoutunnecessary waste of heat through the heating of the material for longerperiods than is necessary for forming the carbid, to provide means in adevice of this class for agitating the walls thereof to prevent unevenflow of the powdered material toward the Zone of activity, and toprovide ready means for discharging the resulting carbid from the de-.

vice. I accomplish these objects by the device shown in the accompanyingdrawings, in which Figure 1 is a vertical section of an electric furnaceconstructed according to my invention. Fig. 2 is a horizontal section ofthe same on the line 2 2 of Fig. 1, being drawn on a slightly-reducedscale.

In the form shown in the drawings the main body of the furnace consistsof two vertically-disposed cylindrical receptacles 3 and 4, openingtoward each other and telescoping each other at their open ends. Theouter and lower receptacle 4 is mounted to slide vertically over thewalls of the inner receptacle 3 and is adapted to be tilted to dischargeits contents after having been withdrawn from its telescoping engagementwith the in ner receptacle.

The receptacle 3 is mounted so as to have a vertical longitudinalreciprocatory movement in the supporting-frame 5. The receptacle 3 isprovided with an outwardly-extending flange 6 at its upper end and issupported upon the heart-shaped cams 7 which engage the flange 6 andthrough rotation of the cams impart the desired vibratory movement tothe receptacle 3. The cams 7 are journaled on the supporting-frame 5 andare geared together to be operated simultaneously by mechanism which isnot shown in the drawings. The movement of the receptacle 3 is guided bythe collar 8, which surrounds the said receptacle, and by the bolts 9,which are secured to the walls of the receptacle and pass through slots10 in the collar 8.

The main body of the receptacle 3 is of tubular form, open both at thetop and bottom, and is preferably formed of metal lined with a coating11 of refractory material. A pair of opposed electrodes 12 are mountedin fixed members 13 of the main supporting frame and extend across thelower end of the receptacle 3. The electrodes are adjustable in themembers 13 in the usual manner for controlling the distance ofseparation of their opposed ends. The outer receptacle 4 is also ofmetal and is similarly lined with a refractory coating 14.

The receptacle 4 is provided with a closed bottom 15, and its verticalwalls are slotted at 16 to fit the parts 17 of the members 13, throughwhich the electrodes enter the interior of the furnace. ported upon avertically disposed screwthreaded shaft or strut 18 and is verticallyadjustable therewith, as will be hereinafter described. The shaft 18 hasthreaded engagement with the hub 19 of a bevel-gear 20. The saidbevel-gear is in turn ournaled in a member 21, which is provided withhorizontally-disposed trunnions 22 and 23, journaled in bearings 24 inthe main supporting-frame. The toothed gear 20 is prevented from shifting axially in its bearing by the collars 25. Rotation of the bevel-gear20 is accomplished by means of a second bevel-gear 26, which meshes withthe bevel-gear 20 and is loosely journaled on the trunnion 23. The bevelgear 26 is provided with a hollow shaft 27, which extends through thebearing 24, concentrically with the trunnion 23, and has keyed to itsend a gear 28, to which power is applied by means of mechanism (notshown) for raising and lowering the receptacle 4. Leakage of molten orsemimolten material through the slots 16 while the receptacle 4 is beinglowered below the lower ends of the receptacle 3 is prevented by meansof the curved guide-plates 29, which have close sliding contact with thewalls of the receptacle 4 in the vicinity of said slots. The upper endsThe receptacle 4 is sup of the guide-plates 29 are steadied by means ofa band 30, and the lower ends are provided with hubs, respectivelyfitting the trunnion 22 and hollow shaft 27. The trunnion 22 is providedat its outer end with a gear 31, connected with suitable mechanism (notshown in the drawings) for rotatingthe trunnions, together with thereceptacle 4 and the guide plates 29, so as to tilt the same toward oneside for the purpose of discharging the contents of said receptacle. Theguide-plates 29 make a close joint at 32 with the members 13, and theirupper ends are curved on the arc of a circle having its center in thetrunnions, so as to permit the plates 29 to rotate about said trunnionswithout interfering with the inemb ers 1 3.

The operation of the device shown is as follows: The powdered materials,such as coke and lime, in the proper proportions for forming calciumcarbid, are filled into the upper end of the receptacle 3. Electriccurrent is then applied to the electrodes, causing an electric arebetween their opposed ends and heating the adjacent particles of matter.This heating is allowed to continue until a Zone of fused carbid isformed in the vicinity of the electrodes. Then the mechanism forrotating the gear 20 is put in operation and the receptacle 4 isgradually drawn down-' ward. The timing of these operations isdetermined in the first instance by experiments and is thereafter alwayssubstantially the same. The speed at which the receptacle 4 is loweredis such that the powdered materials will become thoroughly fused duringtheir passage through the zone of activity that is, the Zone extendingacross the furnace in the neighborhood of the electrodes. During all ofthese operations the inner receptacle 3 is continuously vibrated bymeans of the cams 7, so as to prevent the material from bridging betweenthe walls of the receptacle 3 and interfering with the uniform feedingof the material to the zone of activity. lVhen the outer receptacle 3has been low ered so that its upper edge will clear the bottom of themembers 13, then the operation of the lowering mechanism is stopped andthe mechanism connected with the gear 31 is put into operation fortilting the receptacle 4 to a downwardly-inelined position anddischarging the contents therefrom. The capacity of the whole furnacewhen the receptacles are in the position shown in the drawings issubstantially the same as the capacity of the receptacle 4 after thesame has been withdrawn from engagement with the receptacle 3. Thereceptacle 4 has sufficient capacity to accommodate an entire charge.The timing of the operation of lowering the receptacle 4 is so adjustedthat the e011- tents pass out of the Zone of activity immediately afterbeing formed into calcium earbid, and the calcium carbid in the lowerpart of the receptacle 4 has time to cool to some extent during thedescent of said receptacle to its lowest position. The fact that thegear 26 is journaled concentrically of the trunnion 23 permits thereceptacle 4 to be tilted without disconnecting any of the operatinggearing. l/Vhen the receptacle 4 is tilted, the gear 20 rides on thegear 26, rotating slightly and causing a slight longitudinal movement ofthe shaft 18 within the hub of the gear 20. As soon as the contents ofthe receptacle 4 have been discharged the said receptacle may be rotatedback into a position of alinement with the receptacle 3 and then raisedto its original starting position. The device is now ready to repeat itsoperation, the discharge being rapid and causing but little delay in thecontinuous operation of the furnace.

It will be seen that the device shown will be useful for many otherpurposes besides the manufacture of calcium carbid and that numerousdetails of the construction shown. may be altered without departing fromthe spirit of my invention.

What I claim as my invention, and desire to secure by Letters Patent, is

1. In the electric furnace, the combination of a vertically-disposedtubular receptacle open at the bottom; a second receptacle sur roundingthe first and having a bottom movable in alinement with said firstreceptacle, a pair of electrodes mounted in said frame and. extendinginto the furnace near the lower end of said first receptacle; mechanismfor gradually moving said bottom downwardly away from said electrodes;and mechanism for agitating the walls of said first receptacle,substantially as described.

2. In an electric furnace, the combination of a vertically-disposedtubular receptacle open at the bottom; a second receptacle surroundingthe first and having a bottom movable in alinement with said firstreceptacle, a pair of electrodes mounted in said frame and extendinginto the furnace near the lower end of said first receptacle; mechanismfor gradually moving said bottom downwardly away from said electrodes;and mechanism for causing said first receptacle to reciprocatevertically, substantially as described.

3. In an electric furnace, the combination of a frame; avertically-disposed receptacle mounted in said frame and open at thebottom; a second receptacle open at the top and telescoping with thefirst; a pair of electrodes mounted in said frame and extending into thefurnace near the lower end of said first receptacle; mechanism fordrawing said second receptacle downwardly; and mechanism for agitatingsaid first receptacle, substantially as described.

4. In an electric furnace, the combination of a frame; avertically-disposed tubular receptacle mounted in said frame and open atthe bottom; a second receptacle having tubular walls in axial alinementwith the first receptacle and forming a continuation thereof having abottom movable toward and away: from the lower end of said firstreceptacle, said bottom being movable for a considerable distancewithout breaking the continuity of said walls; and trunnions supportingsaid second receptacle and adapted to permit the same to be tiltedangularly thereon for discharging its contents, substantially asdescribed.

5. In an electric furnace, the combination of a frame; avertically-disposed receptacle mounted in said frame and open at the bottom; a second receptacle open at the top and telescoping with the first;a pair of electrodes mounted in said frame and extending into thefurnace near the lower end of said first receptacle; a strut supportingsaid second receptacle; a member supporting said strut and beingjournaled in said frame on an axis transverse to said strut; mechanismfor adjusting said strut vertically on said member; and mechanismcontrolling the rotation of said member on its axis, substantially asdescribed.

6. In an electric furnace the combination of a frame; avertically-disposed receptacle mounted in said frame and open at the bottom; a second receptacle openat the top and telescoping with the first;a pair of electrodes mounted in said frame and extending into thefurnace, near the lower end of said first receptacle; a member journaledin said frame on an axis transverse to said strut; a threaded hubmeshing with said strut and rotatably mounted on said member; said hubbeing secured against shifting 011 said member longitudinally of saidstrut; and mechanism for rotating said hub for raising and low 'eringsaid second receptacle, substantially as described.

7[ In an electric furnace, the combination of a frame; avertically-disposed receptacle mounted in said frame and open at thebottom; a second receptacle open at the top and telescoping with thefirst; a pair of electrodes mounted in said frame and extending into thefurnace near the lower end of said first receptacle; mechanism fordrawing said second receptacle downward with respect to the first; andmechanism for tilting said second receptacle and discharging itscontents after it has been drawn out of the telescopic engagement withsaid first receptacle, substantially as described.

Signed at Chicago this 23d day of January, 1905.

ED'WIN APPLEBY.

Witnesses:

EUGENE A. RUMMLER, GLEN C. STEPHENS.

